Studies on the effects of prenatal cocaine exposure on infant outcome show an inconsistent pattern of results due, in part, to 1) confounding of cocaine with other substances most notably alcohol; 2) problems in the measurement of prenatal substance exposure; 3) failure to include maternal biobehavioral risk factors related to prenatal substance use that may also affect infant neurobehavioral outcome; and 4) problems with neurobehavioral assessments that may not be sensitive to the effects of prenatal drug exposure. The four objectives of the proposed study are to: 1) determine the combined effects of alcohol and cocaine on infant neurodevelopmental outcome; 2) use sophisticated clinical interview measures of cocaine and alcohol use to provide a more reliable estimate of prenatal substance exposure; 3) include measures of maternal biobehavioral risk factors in addition to measures of prenatal substance exposure that may relate to infant neurobehavioral outcome and 4) use "state of the art" measures from the neurobehavioral battery that we developed for NIDA for the NIH Maternal Lifestyles multicenter longitudinal study of prenatal drug exposure and child outcome. The sample will include 100 infants prenatally exposed to cocaine plus alcohol, only alcohol, and unexposed controls. Marijuana and nicotine exposure, gestational age, and prenatal care will be included as covariates. Mothers will be administered the time line follow-back structured interview method to measure prenatal cocaine and alcohol exposure and a biobehavioral risk factor battery that includes measures of pre-pregnancy substance use history, medical complications, neuropsychological function, mental health issues, familial psychiatric and substance use histories. Infants will be tested at birth and one month on the NICU Network Neurobehavioral Scale and at one month on mother-infant feeding interaction. Data analysis will determine if infants exposed to cocaine and alcohol show poorer neurobehavioral outcome at birth and one month than infants exposed only to alcohol and the effects of maternal biobehavioral risk factors on infant neurobehavioral outcome.